Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 378 · 40 questions

Remember (Find the topic, use the idea): Find the topic: circuit, safety, formula, component, program, sensor or IoT. Use that lesson’s rule — complete loop, V = I × R, P = V × I, last command wins, true → if part. Safety answers are always: low voltage, dry hands, an adult, never the mains.

1. 1.🔁 count = 4
   repeat 2 times { count = count + 3 }
   What is count at the end?
2. 2.🔍 Which sensor would you use to spot someone walking in? (a) a motion sensor (b) a gas sensor (c) a temperature sensor (d) a rain sensor
3. 3.🔁 count = 7
   repeat 10 times { count = count + 5 }
   What is count at the end?
4. 4.📏 Which unit measures how much a part resists? (a) volt (V) (b) watt (W) (c) ohm (Ω) (d) ampere (A)
5. 5.🔺 In the V-I-R triangle, how do we find R? (a) R = V ÷ I (b) R = I ÷ V (c) R = V + I (d) R = V × I
6. 6.🌐 Is a wind-up clock an IoT device? (a) an IoT device (b) not an IoT device
7. 7.Which of these is an input? (a) a buzzer (b) a motor (c) a servo motor (d) a push button
8. 8.True or false: to share camera links is a good habit. (a) True (b) False
9. 9.🔁 What does “count = count + 1” do? (a) prints 1 (b) takes 1 away (c) sets count to 1 (d) adds 1 to count
10. 10.True or false: to set the AC to 24 °C saves electricity. (a) False (b) True
11. 11.Which of these is true of a series circuit? (a) one out, the rest glow (b) bulbs share the voltage (c) many paths for current (d) own switch for each bulb
12. 12.⚙️ Which actuator would you use to open a gate to 90°? (a) a pump (b) a display (c) an LED (d) a servo motor
13. 13.🌈 A resistor has the colour bands brown, orange, black. What is its value (in ohms)?
14. 14.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) becomes zero (b) stays the same (c) gets smaller (d) gets bigger
15. 15.What does a transistor do? (a) limits the current (b) senses how hot it is (c) lets current go one way (d) boosts a small signal
16. 16.📏 How many milliamperes (mA) make 1 ampere? (a) 10 (b) 60 (c) 1000 (d) 100
17. 17.🔁 What does a variable do in a program? (a) blinks an LED (b) measures light (c) joins two wires (d) stores a value
18. 18.⚠️ Is it safe to use a cable with cuts? (a) safe (b) not safe
19. 19.🔢 To get a sensor reading onto a phone, which is the LAST step? (a) the board reads it (b) the app shows it (c) the cloud stores it (d) the sensor measures
20. 20.📏 In the water-pipe picture of a circuit, current is like … (a) the flow of water (b) the water pressure (c) the pipe colour (d) a narrow pipe
21. 21.⏱️ loop forever { LED ON; wait 200 ms; LED OFF; wait 50 ms }
    How many times does the LED blink in 1 second?
22. 22.🗺️ In an input → process → output plan, is “count button presses” the input, the process or the output? (a) input (b) process (c) output
23. 23.🧮 Two equal 40 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
24. 24.🔘 Two switches are in series. When does the bulb glow? (a) when either is ON (b) never (c) when both are OFF (d) when both are ON
25. 25.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a plastic straw across the gap. Does the bulb glow? (a) No (b) Yes
26. 26.True or false: if the switch is ON, the circuit is closed and current flows. (a) True (b) False
27. 27.True or false: “a break stops every bulb” is true of a parallel circuit. (a) True (b) False
28. 28.⚡ A 1.5 W device works on 6 V. What current does it take (in amperes)? =
29. 29.🔐 Which is the strongest password for a home smart camera? (a) password (b) admin (c) Tiger#Lamp42!Moon (d) 123456
30. 30.⚡ Which tiny particles drift along a metal wire to carry the current? (a) photons (b) electrons (c) water drops (d) dust particles
31. 31.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 480 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
32. 32.🤖 if (distance < 30) { buzzer beeps } else { buzzer is silent }
    The distance sensor reads 30 cm. What happens? (a) buzzer is silent (b) buzzer beeps
33. 33.🧮 A 20 Ω resistor is joined in series with two equal 220 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
34. 34.🌈 A resistor has the colour bands violet, grey, orange. What is its value (in ohms)?
35. 35.🌈 A resistor has the colour bands grey, blue, orange. What is its value (in ohms)?
36. 36.🔌 Is a push button an input or an output for a microcontroller? (a) output (b) input
37. 37.🔍 Which is the odd one out? (a) a servo motor (b) an LED (c) a push button (d) a water pump
38. 38.🌐 Each reading a sensor sends is 20 bytes. How many bytes do 150 readings take?
39. 39.🔁 total = 0
    for i = 1 to 8 { total = total + i }
    What is total at the end?
40. 40.🧾 Which lamp gives the same light for the least power? (a) a candle (b) a filament bulb (c) an LED lamp (d) an oil lamp

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